Transfer mechanism for plural compartment concrete mixing drums



Jan. 6, 1948. McMILLAN TRANSFER MECHANISM FOR PLURAL commmwam CONCRETEMIXING mums Filed Dec. 4. 1944 2 Sheets-Sheet 1 A. M MILLAN 2,434,216

TRANSFER MECHANISM FOR PLURAL COMPARTMENT CONCRETE MIXING DRUMS Jan. 6,.1948.

Filed Dec. 4, 1944 2 Sheets-Sheet 2 ,flndrew/ilq/llillarv,

Patented Jan. 6, 1948 TRANSFER MECHANISM FOR PLURAL COM- PARTMENTCONCRETE MIXING DRUMS Andrew McMillan, Milwaukee, Wis., assignor toChain Belt Company, Milwaukee, Wis., a corporation of WisconsinApplication December 4, 1944, Serial No. 566,491

3 Claims.

The invention relates to concrete mixing apparatus, -more especially thekind employing a plural compartment rotatable mixing drum, andrepresents a further development of the apparatus of this characterdisclosed in prior U. S. Patents No. 2,131,682 granted September 2'7,1938, and No. 2,135,436 granted November 1, 1938, on applications filedby Charles F. Ball. More particularly, the invention relates to themechanism for controlling the transfer of the concrete mixture from onecompartment of the drum to the other.

For purposes of disclosure one form of the invention has beenillustrated in the accompanying drawings forming a, part of thisspecification, in which like reference characters designate like partsin all the views, and in which:

Figure 1 is a longitudinal sectional-elevational View of atwo-compartment mixing drum for concrete mixers, in which transfermechanism constructed and arranged in accordance with the invention hasbeen incorporated;

Fig. 2 is an enlarged transverse sectional view on the plane indicatedby the line 2-2 of Fig. 1, looking in the direction of the arrows;

Fig. 3 is a vertical sectional view on the plane indicated by the line33 of Fig. 2, looking in the direction of the arrows, the parts beingshown in the open or transfer positions;

Fig. 4 is a horizontal sectional-plan View, on the plane indicated bythe line 4-4 of Fig. 1, looking down; and

Fig. 5 is a partial transverse sectional view, on a reduced scale, onthe plane indicated by the line 5-5 of Fig. 3.

The drum l illustrated in Fig. 1 is of a type widely used in concretemixers of the paving and other types and its heads H and 12 arerespectively provided with the charging opening I3 and the dischargingopening M, with the former of which is associated a charging chute lfixedly carried by the framework of the machine and adapted to receivethe aggregates and cement from the charging skip, not shown, forcharging into the drum through the said opening l3. A discharge chute I6is pivotally mounted at I! adjacent the discharge opening 14 forswinging movements from the discharge position shown to an oppositelyinclined non-discharge position outside the drum, such movements beingeffected by means of a power discharge mechanism ill of well known formthrough appropriate linkage l9.

Medially between its ends the drum is provided with a transversepartition structure 2| dividing it into two chambers or compartments 22and 23 in each of which are drum-carried mixing blades of known form,some of those in compartment 22 bein indicated at 24. As will be readilyunderstood by those skilled in the art, a batch of concrete constituentsis introduced into the primary compartment 22, there mixed for a portiononly of the required mixing period, then transferred to secondarycompartment 23, and while its mixing is being completed therein a freshbatch of materials is fed into and preliminarily mixed in compartment22. Thus, two batches are handled simultaneously and a material increasein the output of the machine attained as compared to that of a singlecompartment drum.

The partition structure 2! comprises an annulus 25 disposedsubstantially perpendicular to the axis of the drum and having its outerperipheral portion secured to the drum wall, as by an angle bracket 26.To its inner periphery is welded or otherwise secured a frusto-conicalannulus 21 which also extends to the drum wall, as shown in Fig. l. Theinterior of the annulus 21 is provided with a truncated coniform liner23 which, as best shown in Fig. 3, projects through the opening in theannular structure 25, 21 and into the chamber 23. Upon the projectingportion of the line 28 is seated a frusto-conical annulus 29 providedwith an outer peripheral flange 3!! which is secured by bolts 3| to theannulus 25. The inner periphery of the annulus 29 carries a seating ring32, surrounding the transfer opening 33 of the partition structure,provided by the openings of the annuli 2B and 29.

Mounted upon th annulus 29 and extending into the chamber 23 is a spiderstructure 35 comprising a plurality of circumferentially spaced arms 36,one end of each of which is attached as by a bolt 31 to an angle bracket38 welded or otherwise secured to the" annulus 29. Each arm is curved asat 39 to extend radially inward toward the axis of the drum, and theinner ends are secured as by bolts 40 to a ring 4|. Each arm also has aspline plate 42 adjustably secured to its inner end by bolts 43; Theinner ends of the spline plates 32 are slidably received in grooves orkeyways 44 provided in members 45 rigidly carried by a sleeve 46 whichin turn is rigidly mounted upon one end portion of a shaft 41 extendingaxially of the drum. Adjacent the sleeve 46 and within the spiderstructure 35, the said shaft 41 carries a transfer-control door 48 whichas best shown in Fig. 3, comprises a dished disc 49 mounted upon thesaid shaft by a ball and socket joint structure 50 and provided at itsouter periphery with a yieldable packing ring 5| adapted for sealingengagement with the seating ring 32. The joint 59 is enclosed within aflexible housing 52 whereby it is protected against the concrete mixturewhile at the same time universal movement of the door 48 is permitted toenable it to fully seat the packing 5| against the ring 32 The shaft 41extends forwardly, i. e. toward the charging end of the machine, throughthe transfer opening 33 and into the chamber 22 51 and by a transversebrace member 58 to a:' sleeve 59 which is providedwith bearings 611m,which the shaft 41 is journalled. Relative 6nd,.

wise movement between the shaft and the fork structure in one directionis prevented by-a splits washer 62 mounted in a groove 63- in the shaftand abutting a thrust bearing 64. A cap 65 covers the end of the shaft41 andthrough engagement therewith and/or with the washer 62, preventsendwise movement in the opposite direction. Thus, reciprocatingmovements may be imparted to the shaft by the fork structureto move thetransfer door 48 to and from engagement with the-seating ring, 32;whileat the same time the shaft-and? door are free to; rotate with thedrum andpartition structure;

Aslwilkbe oleartfrom-Fig; Lthe arms SG-of the fork structureextendzthroughi the charging openingi iii: of." the drum. one. toeitherside of the charging chute.l;,and-at-theirforward nds t y are connected:to; a. lever t5. which is actuated throughla linkilifi by'a powermechanism 61, similar to-themeohanism l8;which actuates the dischargechute 15.. The me hanisms. I8 and which: maybe; of the eneral typedisclosed in prion U; S; Patent No.1,4-15A11 to Samuel Shafer, Jn,are=operatediin appropriately timed relation whereby the discharge:chute lfiis moved to the diso'hargingposition of Figal only-when thetransfor; door iszclosed, and? conver ely t Said. or'is moved: to the:open position; of Fig 3' only when the chute. I 65115; in itsnonrdischarging position.

Thespider; structure 35; being rigidly mounted on the partitionstructure 2-! and being located in theesecond-fcompartment 2350f thedrum, provides mettle-members 42,- 45 a sturdy outboard spline bearingfor;theex-tremeend portionof the shaft 41: which. bearin bein beh nd tho r .48 i completelyo lt of the pathrof' the concretemixtulfeiduringtransfer-from one compartment to thin other-andthusoifersnoimpediment whatever-to such; transfer. Furthermore, the arms 36;o f;the Spider; structure 35are; preferably disposed;- circumferentiallyintermediate the discharge pprtionslfl"v of the bIadesZ i-ofcompartmentqzz (whichbladesas is well known, move the mixturato and,through-the-transfer opening 33) nd therefore the said arms ofie-raminimum of interference to the-transfer.

To; facilitate'and speed up the transfer of 4 the mixturefrom;the-compartment 22 throughthe opening; 33: into compartment 23; theshaft 41 may be providedwitna plurality of longitudinallyextendinavanesorfins lflswhich arewelded or otherwise rigidly-secured,to-the shaft for rotation andl longitudinal movement therewith. Thesefinsareso disposed upon the shaft that in the'normalposition-of theparts they are 'retztacted from the; transfer opening 33, as shownin-Fig. 1, soasnot tointerfere with the mixing action of; the, blades24- andv transfer scoops 24'. However, when the shaft 41 ismoved towardthe left to openjthe door 48'for transfer of themixturefrom;one-compartment to the other, the vanes. 10 move with-thesaid shaft to positions within or immediately adjacent the, opening 33,as show n in Fig. 3, wherethey may deflect-the mixture as it isdischarged by the scoops 24' and translate its rotary motion-intolongitudinal motionthereby facilitating itspassagethrough thesaidppening.

0 Number 4 While one form of the invention has been illustrated anddescribed for purposes of disclosure, it is obvious that those skilledinthe art may vary the details of construction as well as the .precisearrangement of parts without departing from they spirit of theinvention, and therefore it is. not wished tobe limited to the abovedisclosure except as may be required by the claims.

What is claimed is: t

1. In a concrete mixing drum, having a transverse partition dividing itinto primary and secondary mixing compartments, which partition isprovided with a transfer opening for the mixture, said drum also havingrotatable elements in said primary compartment for moving the mixturetoward said, opening; a door mounted for reciprocation. axially of theopening whereby to controltransfer of mixture therethrough; and membersdisposed adjacent the opening and axially. reciprocatable with the doorfrom a position removed. from the opening when the door is closed, toaposition adjacent the opening when the door is open, whereby in thelatter position they may deflect mixture from said rotatable elementsthrough the opening.

2. In a concrete mixing drum, having a transverse partition dividing itinto primary and secondary mixing compartments, which partition isprovided with a transfer opening for the mixture, saidldrum also havingrotatable elements in said primary compartment for moving the mixturetowardsaid opening; a reciprocatable shaft mounted. axially of theopening; a door carried by the shaft for movements to and from theopening whereby to control transfer of the mixture there: through; andfins carried by the shaft for move-. ment from a position removed fromthe opening whenthe door is closed, to a position adjacent the openingwhen the door is open, whereby in the latter position they may deflectmixture from said rotatable elements through the opening.

3. In a concrete mixing drum, having a transverse partition dividing itinto primary and secondary mixing compartments, which partition isprovided with a transfer opening for the mixture, said drum also havingrotatable elements in said primary compartment for moving the mixturetoward said opening; a reciprocatable shaft mounted axially of theopening; a door carried by said shaft within the secondary compartmentfor movements to and from the opening whereby to control transfer of themixture through the latter; and fins carried by the shaft within theprimary compartment for movement simultaneously with the door from aposition removed from the. opening when the door is closed, to aposition adjacent the opening when the door is open, whereby in thelatter position they may translate motion. of the mixture discharged bysaid rotatable elements and facilitate its passage through the opening.

ANDREW MCMILLAN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Name Date Faber May 24, 1921 Webb Apr. 10, 1928Ball Nov. 1, 1938 Reed Jan. 10, 1911 Cutler Dec.3, 1949

